IS1327, a New Insertion-Like Element in the Pathogenicity-Associated Plasmid of Erwinia herbicola pv. gypsophilae. Amnon Lichter. Department of Botany, Tel Aviv University, Tel Aviv 69978, Israel. Shulamit Manulis (2), Lea Valinsky (2), Baruch Karniol (1), and Isaac Barash(1). (1) Department of Botany, Tel Aviv University, Tel Aviv 69978, Israel; and (2)Department of Plant Pathology, ARO, the Volcani Center, P.O.B. 6, Bet Dagan 50250, Israel. MPMI 9:098-104. Accepted 10 October 1995, Copyright 1996 The American Phytopathological Society.

The pathogenicity-associated plasmid (pPATH) of Erwinia herbicola pv. gypsophilae was previously shown to be exclusively present in pathogenic strains and to contain a gene cluster encoding phytohonnone biosynthesis. Sequence analysis of the DNA region located downstream from the cytokinin biosynthetic gene (etz) revealed homology to insertion sequences (IS) of the IS6 family. Southern blot analysis performed on plasmid DNA of E. herbicola pv. gypsophilae revealed the presence of six copies of this insertion-like element, which was designated as IS/J27. Only pathogenic strains contained 1S1327 and restriction fragment length polymorphism was observed among gyp-sophila and beet pathovars of E. herbicola. Nonpathogenic deletion derivatives of pPATH contained fewer copies of 1S1327, suggesting its presence in the deleted region. One copy of IS/327 (IS/327-R) was located 2.8 kb downstream from the IS element adjacent to the etz (IS1327-L) in a direct repeat.